body{
    display: flex;
    /* 主轴为垂直方向，起点在上沿 */
    flex-direction: column;
}
.main{
    flex: 1;
    overflow-y: scroll;

    .latest, .kecheng {
        padding: 14px;
        h3 {
          margin-bottom: 14px;
        }
        > a {
          box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
          border-radius: 10px;
          overflow: hidden;
          display: block;
          color: black;
      
          div {
            height: 120px;
            background-repeat: no-repeat;
            background-position: center center;
            background-size: cover;
          }
          img {
            width: 100%;
            height: 180px;
          }
          h4 {
            padding: 16px;
          }
          p {
            padding: 0 16px;
            padding-bottom: 16px;
          }
        }
      }
}

.course{
    margin-bottom: 15px;
}
